diff mbox series

[v10,52/55] input: touchscreen: atmel_mxt_ts: Added sysfs entry for touchscreen status

Message ID 20200331105051.58896-53-jiada_wang@mentor.com (mailing list archive)
State Superseded
Headers show
Series atmel_mxt_ts misc | expand

Commit Message

Wang, Jiada March 31, 2020, 10:50 a.m. UTC 
From: Naveen Chakka <Naveen.Chakka@in.bosch.com>

To know the current communication status of the touch controller during
runtime, sysfs interface is added

sysfs interface: /sys/class/i2c-dev/i2c-*/device/*/touch_dev_stat
Executing the above sysfs interface provides two output values

1)Status of the touch device
	value 0 represents device is inactive
	value 1 represents device is active
2)Error counter
	value represents the number of times device in inactive since last read

New module_param "debug_state" is introduced, by set its value,
a watchdog work is scheduled to periodically check device state.
default value is false.

Signed-off-by: Naveen Chakka <Naveen.Chakka@in.bosch.com>
Signed-off-by: Sanjeev Chugh <sanjeev_chugh@mentor.com>
Signed-off-by: George G. Davis <george_davis@mentor.com>
[jiada: Rename mxt_touch_device_status to touch_dev_stat_show
	Replace DEVICE_ATTR to DEVICE_ATTR_RO]
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 90 ++++++++++++++++++++++--
 1 file changed, 83 insertions(+), 7 deletions(-)

Comments

Dmitry Osipenko March 31, 2020, 3:08 p.m. UTC | #1 
31.03.2020 13:50, Jiada Wang пишет:
...
> +static void mxt_watchdog_work(struct work_struct *work)
> +{
> +	struct mxt_data *data =
> +		container_of(work, struct mxt_data, watchdog_work.work);
> +	u16 info_buf;
> +	int ret;
> +
> +	if (data->suspended || data->in_bootloader ||
> +	    data->mxt_status.intp_triggered)
> +		goto sched_work;

Won't it become a problem if other thread puts device into suspended /
bootloader state in the same time?

> +	ret = __mxt_read_reg(data->client, 0, sizeof(info_buf), &info_buf);
> +
> +	if (ret) {
> +		data->mxt_status.error_count++;
> +		data->mxt_status.dev_status = false;
> +	} else {
> +		data->mxt_status.dev_status = true;
> +	}
> +
> +sched_work:
> +	schedule_delayed_work(&data->watchdog_work,
> +			      msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
> +}
...

> @@ -4329,6 +4390,12 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  		msleep(MXT_RESET_TIME);
>  	}
>  
> +	if (debug_state) {
> +		INIT_DELAYED_WORK(&data->watchdog_work, mxt_watchdog_work);
> +		schedule_delayed_work(&data->watchdog_work,
> +				      msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
> +	}
> +
>  	error = mxt_initialize(data);
>  	if (error)
>  		goto err_free_object;
> @@ -4343,6 +4410,8 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  	return 0;
>  
>  err_free_object:
> +	if (debug_state)
> +		cancel_delayed_work_sync(&data->watchdog_work);
>  	mxt_free_input_device(data);
>  	mxt_free_object_table(data);
>  	if (data->reset_gpio) {
> @@ -4367,6 +4436,9 @@ static int mxt_remove(struct i2c_client *client)
>  	mxt_free_input_device(data);
>  	mxt_free_object_table(data);
>  
> +	if (debug_state)
> +		cancel_delayed_work_sync(&data->watchdog_work);

What will happen if debug_state was false during of mxt_probe() and then
the debug_state parameter was changed to true via sysfs?

I think the INIT_DELAYED_WORK() and cancel_delayed_work_sync() should be
invoked unconditionally.

>  	return 0;
>  }
>  
> @@ -4463,3 +4535,7 @@ module_i2c_driver(mxt_driver);
>  MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
>  MODULE_DESCRIPTION("Atmel maXTouch Touchscreen driver");
>  MODULE_LICENSE("GPL");
> +
> +module_param(debug_state, bool, 0);
> +MODULE_PARM_DESC(debug_state, "Enable/Disable watchdog work to check device state (default="
> +		 __MODULE_STRING(MXT_DEBUG_STATE) ")");
> 

The "default=..." part of MODULE_PARM_DESC() probably isn't really
useful and could be omitted, don't you think so?
Wang, Jiada April 1, 2020, 12:51 p.m. UTC | #2 
Hi Dmitry

Thanks for your comments

On 2020/04/01 0:08, Dmitry Osipenko wrote:
> 31.03.2020 13:50, Jiada Wang пишет:
> ...
>> +static void mxt_watchdog_work(struct work_struct *work)
>> +{
>> +	struct mxt_data *data =
>> +		container_of(work, struct mxt_data, watchdog_work.work);
>> +	u16 info_buf;
>> +	int ret;
>> +
>> +	if (data->suspended || data->in_bootloader ||
>> +	    data->mxt_status.intp_triggered)
>> +		goto sched_work;
> 
> Won't it become a problem if other thread puts device into suspended /
> bootloader state in the same time?
> 
right, I will use mutex lock to prevent such case.
also I think data->mxt_status.intp_triggered isn't necessary,
when lock is used.

>> +	ret = __mxt_read_reg(data->client, 0, sizeof(info_buf), &info_buf);
>> +
>> +	if (ret) {
>> +		data->mxt_status.error_count++;
>> +		data->mxt_status.dev_status = false;
>> +	} else {
>> +		data->mxt_status.dev_status = true;
>> +	}
>> +
>> +sched_work:
>> +	schedule_delayed_work(&data->watchdog_work,
>> +			      msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
>> +}
> ...
> 
>> @@ -4329,6 +4390,12 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
>>   		msleep(MXT_RESET_TIME);
>>   	}
>>   
>> +	if (debug_state) {
>> +		INIT_DELAYED_WORK(&data->watchdog_work, mxt_watchdog_work);
>> +		schedule_delayed_work(&data->watchdog_work,
>> +				      msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
>> +	}
>> +
>>   	error = mxt_initialize(data);
>>   	if (error)
>>   		goto err_free_object;
>> @@ -4343,6 +4410,8 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
>>   	return 0;
>>   
>>   err_free_object:
>> +	if (debug_state)
>> +		cancel_delayed_work_sync(&data->watchdog_work);
>>   	mxt_free_input_device(data);
>>   	mxt_free_object_table(data);
>>   	if (data->reset_gpio) {
>> @@ -4367,6 +4436,9 @@ static int mxt_remove(struct i2c_client *client)
>>   	mxt_free_input_device(data);
>>   	mxt_free_object_table(data);
>>   
>> +	if (debug_state)
>> +		cancel_delayed_work_sync(&data->watchdog_work);
> 
> What will happen if debug_state was false during of mxt_probe() and then
> the debug_state parameter was changed to true via sysfs?

module_param debug_state is added with permission 0,
so it's value won't change during driver operation
> 
> I think the INIT_DELAYED_WORK() and cancel_delayed_work_sync() should be
> invoked unconditionally.
> 
>>   	return 0;
>>   }
>>   
>> @@ -4463,3 +4535,7 @@ module_i2c_driver(mxt_driver);
>>   MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
>>   MODULE_DESCRIPTION("Atmel maXTouch Touchscreen driver");
>>   MODULE_LICENSE("GPL");
>> +
>> +module_param(debug_state, bool, 0);
>> +MODULE_PARM_DESC(debug_state, "Enable/Disable watchdog work to check device state (default="
>> +		 __MODULE_STRING(MXT_DEBUG_STATE) ")");
>>
> 
> The "default=..." part of MODULE_PARM_DESC() probably isn't really
> useful and could be omitted, don't you think so?
> 
since debug_state can't be updated via sysfs, so I think add it's 
default in MODULE_PARM_DESC() is useful? what's your opinion?

Thanks,
Jiada
Dmitry Osipenko April 1, 2020, 2:33 p.m. UTC | #3 
01.04.2020 15:51, Wang, Jiada пишет:
> Hi Dmitry
> 
> Thanks for your comments
> 
> On 2020/04/01 0:08, Dmitry Osipenko wrote:
>> 31.03.2020 13:50, Jiada Wang пишет:
>> ...
>>> +static void mxt_watchdog_work(struct work_struct *work)
>>> +{
>>> +    struct mxt_data *data =
>>> +        container_of(work, struct mxt_data, watchdog_work.work);
>>> +    u16 info_buf;
>>> +    int ret;
>>> +
>>> +    if (data->suspended || data->in_bootloader ||
>>> +        data->mxt_status.intp_triggered)
>>> +        goto sched_work;
>>
>> Won't it become a problem if other thread puts device into suspended /
>> bootloader state in the same time?
>>
> right, I will use mutex lock to prevent such case.
> also I think data->mxt_status.intp_triggered isn't necessary,
> when lock is used.
> 
>>> +    ret = __mxt_read_reg(data->client, 0, sizeof(info_buf), &info_buf);
>>> +
>>> +    if (ret) {
>>> +        data->mxt_status.error_count++;
>>> +        data->mxt_status.dev_status = false;
>>> +    } else {
>>> +        data->mxt_status.dev_status = true;
>>> +    }
>>> +
>>> +sched_work:
>>> +    schedule_delayed_work(&data->watchdog_work,
>>> +                  msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
>>> +}
>> ...
>>
>>> @@ -4329,6 +4390,12 @@ static int mxt_probe(struct i2c_client
>>> *client, const struct i2c_device_id *id)
>>>           msleep(MXT_RESET_TIME);
>>>       }
>>>   +    if (debug_state) {
>>> +        INIT_DELAYED_WORK(&data->watchdog_work, mxt_watchdog_work);
>>> +        schedule_delayed_work(&data->watchdog_work,
>>> +                      msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
>>> +    }
>>> +
>>>       error = mxt_initialize(data);
>>>       if (error)
>>>           goto err_free_object;
>>> @@ -4343,6 +4410,8 @@ static int mxt_probe(struct i2c_client *client,
>>> const struct i2c_device_id *id)
>>>       return 0;
>>>     err_free_object:
>>> +    if (debug_state)
>>> +        cancel_delayed_work_sync(&data->watchdog_work);
>>>       mxt_free_input_device(data);
>>>       mxt_free_object_table(data);
>>>       if (data->reset_gpio) {
>>> @@ -4367,6 +4436,9 @@ static int mxt_remove(struct i2c_client *client)
>>>       mxt_free_input_device(data);
>>>       mxt_free_object_table(data);
>>>   +    if (debug_state)
>>> +        cancel_delayed_work_sync(&data->watchdog_work);
>>
>> What will happen if debug_state was false during of mxt_probe() and then
>> the debug_state parameter was changed to true via sysfs?
> 
> module_param debug_state is added with permission 0,
> so it's value won't change during driver operation

Thank you for the clarification, I didn't realize that setting
permission to 0 hides the parameter completely in sysfs.

>> I think the INIT_DELAYED_WORK() and cancel_delayed_work_sync() should be
>> invoked unconditionally.
>>
>>>       return 0;
>>>   }
>>>   @@ -4463,3 +4535,7 @@ module_i2c_driver(mxt_driver);
>>>   MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
>>>   MODULE_DESCRIPTION("Atmel maXTouch Touchscreen driver");
>>>   MODULE_LICENSE("GPL");
>>> +
>>> +module_param(debug_state, bool, 0);
>>> +MODULE_PARM_DESC(debug_state, "Enable/Disable watchdog work to check
>>> device state (default="
>>> +         __MODULE_STRING(MXT_DEBUG_STATE) ")");
>>>
>>
>> The "default=..." part of MODULE_PARM_DESC() probably isn't really
>> useful and could be omitted, don't you think so?
>>
> since debug_state can't be updated via sysfs, so I think add it's
> default in MODULE_PARM_DESC() is useful? what's your opinion?

If you want to keep the "default" kept in the description, then perhaps
a simple "default=false" should be enough because nothing would be able
to change it to true.
Dmitry Osipenko April 1, 2020, 4:10 p.m. UTC | #4 
01.04.2020 17:33, Dmitry Osipenko пишет:
> 01.04.2020 15:51, Wang, Jiada пишет:
>> Hi Dmitry
>>
>> Thanks for your comments
>>
>> On 2020/04/01 0:08, Dmitry Osipenko wrote:
>>> 31.03.2020 13:50, Jiada Wang пишет:
>>> ...
>>>> +static void mxt_watchdog_work(struct work_struct *work)
>>>> +{
>>>> +    struct mxt_data *data =
>>>> +        container_of(work, struct mxt_data, watchdog_work.work);
>>>> +    u16 info_buf;
>>>> +    int ret;
>>>> +
>>>> +    if (data->suspended || data->in_bootloader ||
>>>> +        data->mxt_status.intp_triggered)
>>>> +        goto sched_work;
>>>
>>> Won't it become a problem if other thread puts device into suspended /
>>> bootloader state in the same time?
>>>
>> right, I will use mutex lock to prevent such case.
>> also I think data->mxt_status.intp_triggered isn't necessary,
>> when lock is used.

Won't it be cleaner to stop/start the watchdog instead of messing with
the locks?

>>>> +    ret = __mxt_read_reg(data->client, 0, sizeof(info_buf), &info_buf);
>>>> +
>>>> +    if (ret) {
>>>> +        data->mxt_status.error_count++;
>>>> +        data->mxt_status.dev_status = false;
>>>> +    } else {
>>>> +        data->mxt_status.dev_status = true;
>>>> +    }
>>>> +
>>>> +sched_work:
>>>> +    schedule_delayed_work(&data->watchdog_work,
>>>> +                  msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
>>>> +}
>>> ...
>>>
>>>> @@ -4329,6 +4390,12 @@ static int mxt_probe(struct i2c_client
>>>> *client, const struct i2c_device_id *id)
>>>>           msleep(MXT_RESET_TIME);
>>>>       }
>>>>   +    if (debug_state) {
>>>> +        INIT_DELAYED_WORK(&data->watchdog_work, mxt_watchdog_work);
>>>> +        schedule_delayed_work(&data->watchdog_work,
>>>> +                      msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
>>>> +    }
>>>> +
>>>>       error = mxt_initialize(data);
>>>>       if (error)
>>>>           goto err_free_object;
>>>> @@ -4343,6 +4410,8 @@ static int mxt_probe(struct i2c_client *client,
>>>> const struct i2c_device_id *id)
>>>>       return 0;
>>>>     err_free_object:
>>>> +    if (debug_state)
>>>> +        cancel_delayed_work_sync(&data->watchdog_work);
>>>>       mxt_free_input_device(data);
>>>>       mxt_free_object_table(data);
>>>>       if (data->reset_gpio) {
>>>> @@ -4367,6 +4436,9 @@ static int mxt_remove(struct i2c_client *client)
>>>>       mxt_free_input_device(data);
>>>>       mxt_free_object_table(data);
>>>>   +    if (debug_state)
>>>> +        cancel_delayed_work_sync(&data->watchdog_work);
>>>
>>> What will happen if debug_state was false during of mxt_probe() and then
>>> the debug_state parameter was changed to true via sysfs?
>>
>> module_param debug_state is added with permission 0,
>> so it's value won't change during driver operation
> 
> Thank you for the clarification, I didn't realize that setting
> permission to 0 hides the parameter completely in sysfs.

Anyways, I'm still thinking that the condition removal will make code
cleaner a tad.
Wang, Jiada April 6, 2020, 6:59 a.m. UTC | #5 
Hi Dmitry

On 2020/04/02 1:10, Dmitry Osipenko wrote:
> 01.04.2020 17:33, Dmitry Osipenko пишет:
>> 01.04.2020 15:51, Wang, Jiada пишет:
>>> Hi Dmitry
>>>
>>> Thanks for your comments
>>>
>>> On 2020/04/01 0:08, Dmitry Osipenko wrote:
>>>> 31.03.2020 13:50, Jiada Wang пишет:
>>>> ...
>>>>> +static void mxt_watchdog_work(struct work_struct *work)
>>>>> +{
>>>>> +    struct mxt_data *data =
>>>>> +        container_of(work, struct mxt_data, watchdog_work.work);
>>>>> +    u16 info_buf;
>>>>> +    int ret;
>>>>> +
>>>>> +    if (data->suspended || data->in_bootloader ||
>>>>> +        data->mxt_status.intp_triggered)
>>>>> +        goto sched_work;
>>>>
>>>> Won't it become a problem if other thread puts device into suspended /
>>>> bootloader state in the same time?
>>>>
>>> right, I will use mutex lock to prevent such case.
>>> also I think data->mxt_status.intp_triggered isn't necessary,
>>> when lock is used.
> 
> Won't it be cleaner to stop/start the watchdog instead of messing with
> the locks?
> 
will stop/start watchdog work when necessary in next version

Thanks,
Jiada
>>>>> +    ret = __mxt_read_reg(data->client, 0, sizeof(info_buf), &info_buf);
>>>>> +
>>>>> +    if (ret) {
>>>>> +        data->mxt_status.error_count++;
>>>>> +        data->mxt_status.dev_status = false;
>>>>> +    } else {
>>>>> +        data->mxt_status.dev_status = true;
>>>>> +    }
>>>>> +
>>>>> +sched_work:
>>>>> +    schedule_delayed_work(&data->watchdog_work,
>>>>> +                  msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
>>>>> +}
>>>> ...
>>>>
>>>>> @@ -4329,6 +4390,12 @@ static int mxt_probe(struct i2c_client
>>>>> *client, const struct i2c_device_id *id)
>>>>>            msleep(MXT_RESET_TIME);
>>>>>        }
>>>>>    +    if (debug_state) {
>>>>> +        INIT_DELAYED_WORK(&data->watchdog_work, mxt_watchdog_work);
>>>>> +        schedule_delayed_work(&data->watchdog_work,
>>>>> +                      msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
>>>>> +    }
>>>>> +
>>>>>        error = mxt_initialize(data);
>>>>>        if (error)
>>>>>            goto err_free_object;
>>>>> @@ -4343,6 +4410,8 @@ static int mxt_probe(struct i2c_client *client,
>>>>> const struct i2c_device_id *id)
>>>>>        return 0;
>>>>>      err_free_object:
>>>>> +    if (debug_state)
>>>>> +        cancel_delayed_work_sync(&data->watchdog_work);
>>>>>        mxt_free_input_device(data);
>>>>>        mxt_free_object_table(data);
>>>>>        if (data->reset_gpio) {
>>>>> @@ -4367,6 +4436,9 @@ static int mxt_remove(struct i2c_client *client)
>>>>>        mxt_free_input_device(data);
>>>>>        mxt_free_object_table(data);
>>>>>    +    if (debug_state)
>>>>> +        cancel_delayed_work_sync(&data->watchdog_work);
>>>>
>>>> What will happen if debug_state was false during of mxt_probe() and then
>>>> the debug_state parameter was changed to true via sysfs?
>>>
>>> module_param debug_state is added with permission 0,
>>> so it's value won't change during driver operation
>>
>> Thank you for the clarification, I didn't realize that setting
>> permission to 0 hides the parameter completely in sysfs.
> 
> Anyways, I'm still thinking that the condition removal will make code
> cleaner a tad.
>
diff mbox series

Patch

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 14bd64d194b0..dda10bb51cb3 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -222,6 +222,7 @@  enum t100_type {
 #define MXT_CHG_DELAY		100	/* msec */
 #define MXT_POWERON_DELAY	150	/* msec */
 #define MXT_BOOTLOADER_WAIT	36E5	/* 1 minute */
+#define MXT_WATCHDOG_TIMEOUT	1000	/* msec */
 
 /* Command to unlock bootloader */
 #define MXT_UNLOCK_CMD_MSB	0xaa
@@ -245,6 +246,9 @@  enum t100_type {
 
 #define DEBUG_MSG_MAX		200
 
+#define MXT_DEBUG_STATE		false
+static bool debug_state = MXT_DEBUG_STATE;
+
 struct mxt_info {
 	u8 family_id;
 	u8 variant_id;
@@ -317,6 +321,12 @@  struct mxt_flash {
 	struct delayed_work work;
 };
 
+struct mxt_statusinfo {
+	bool dev_status;
+	bool intp_triggered;
+	u32 error_count;
+};
+
 /* Each client has this additional data */
 struct mxt_data {
 	struct i2c_client *client;
@@ -372,6 +382,8 @@  struct mxt_data {
 	const char *pcfg_name;
 	const char *input_name;
 	struct mxt_flash *flash;
+	struct delayed_work watchdog_work;
+	struct mxt_statusinfo mxt_status;
 
 	/* Cached parameters from object table */
 	u16 T5_address;
@@ -1626,6 +1638,8 @@  static irqreturn_t mxt_interrupt(int irq, void *dev_id)
 	struct mxt_data *data = dev_id;
 	int ret;
 
+	data->mxt_status.intp_triggered = true;
+
 	if (data->in_bootloader) {
 		complete(&data->chg_completion);
 
@@ -1633,21 +1647,25 @@  static irqreturn_t mxt_interrupt(int irq, void *dev_id)
 			cancel_delayed_work_sync(&data->flash->work);
 
 		ret = mxt_check_bootloader(data);
-		return IRQ_RETVAL(ret);
+		ret = IRQ_RETVAL(ret);
+		goto exit;
 	}
 
-	if (!data->object_table)
-		return IRQ_HANDLED;
+	if (!data->object_table) {
+		ret = IRQ_HANDLED;
+		goto exit;
+	}
 
 	if (data->T44_address)
 		ret = mxt_process_messages_t44(data);
 	else
 		ret = mxt_process_messages(data);
 
-	if (ret <= 0)
-		return IRQ_NONE;
-	else
-		return IRQ_HANDLED;
+	ret = (ret <= 0) ? IRQ_NONE : IRQ_HANDLED;
+
+exit:
+	data->mxt_status.intp_triggered = false;
+	return ret;
 }
 
 static int mxt_t6_command(struct mxt_data *data, u16 cmd_offset,
@@ -2969,6 +2987,31 @@  static int mxt_bootloader_status(struct mxt_data *data)
 	return 0;
 }
 
+static void mxt_watchdog_work(struct work_struct *work)
+{
+	struct mxt_data *data =
+		container_of(work, struct mxt_data, watchdog_work.work);
+	u16 info_buf;
+	int ret;
+
+	if (data->suspended || data->in_bootloader ||
+	    data->mxt_status.intp_triggered)
+		goto sched_work;
+
+	ret = __mxt_read_reg(data->client, 0, sizeof(info_buf), &info_buf);
+
+	if (ret) {
+		data->mxt_status.error_count++;
+		data->mxt_status.dev_status = false;
+	} else {
+		data->mxt_status.dev_status = true;
+	}
+
+sched_work:
+	schedule_delayed_work(&data->watchdog_work,
+			      msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
+}
+
 static int mxt_initialize(struct mxt_data *data)
 {
 	struct i2c_client *client = data->client;
@@ -3956,6 +3999,22 @@  static const struct attribute_group mxt_fw_attr_group = {
 	.attrs = mxt_fw_attrs,
 };
 
+static ssize_t touch_dev_stat_show(struct device *dev, struct
+				   device_attribute * attr, char *buf)
+{
+	struct mxt_data *data = dev_get_drvdata(dev);
+	int ret = 0;
+
+	if (data->mxt_status.dev_status)
+		data->mxt_status.error_count = 0;
+
+	ret =  snprintf(buf, PAGE_SIZE, "%d %d\n", data->mxt_status.dev_status,
+			data->mxt_status.error_count);
+	/* clear the error counter once it is read */
+	data->mxt_status.error_count = 0;
+	return ret;
+}
+
 static DEVICE_ATTR_RO(fw_version);
 static DEVICE_ATTR_RO(hw_version);
 static DEVICE_ATTR(object, S_IRUGO, mxt_object_show, NULL);
@@ -3965,6 +4024,7 @@  static DEVICE_ATTR_RW(debug_enable);
 static DEVICE_ATTR_RW(debug_v2_enable);
 static DEVICE_ATTR_RO(debug_notify);
 static DEVICE_ATTR_RW(t25_selftest);
+static DEVICE_ATTR_RO(touch_dev_stat);
 
 static struct attribute *mxt_attrs[] = {
 	&dev_attr_fw_version.attr,
@@ -3976,6 +4036,7 @@  static struct attribute *mxt_attrs[] = {
 	&dev_attr_debug_v2_enable.attr,
 	&dev_attr_debug_notify.attr,
 	&dev_attr_t25_selftest.attr,
+	&dev_attr_touch_dev_stat.attr,
 	NULL
 };
 
@@ -4329,6 +4390,12 @@  static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		msleep(MXT_RESET_TIME);
 	}
 
+	if (debug_state) {
+		INIT_DELAYED_WORK(&data->watchdog_work, mxt_watchdog_work);
+		schedule_delayed_work(&data->watchdog_work,
+				      msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
+	}
+
 	error = mxt_initialize(data);
 	if (error)
 		goto err_free_object;
@@ -4343,6 +4410,8 @@  static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	return 0;
 
 err_free_object:
+	if (debug_state)
+		cancel_delayed_work_sync(&data->watchdog_work);
 	mxt_free_input_device(data);
 	mxt_free_object_table(data);
 	if (data->reset_gpio) {
@@ -4367,6 +4436,9 @@  static int mxt_remove(struct i2c_client *client)
 	mxt_free_input_device(data);
 	mxt_free_object_table(data);
 
+	if (debug_state)
+		cancel_delayed_work_sync(&data->watchdog_work);
+
 	return 0;
 }
 
@@ -4463,3 +4535,7 @@  module_i2c_driver(mxt_driver);
 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
 MODULE_DESCRIPTION("Atmel maXTouch Touchscreen driver");
 MODULE_LICENSE("GPL");
+
+module_param(debug_state, bool, 0);
+MODULE_PARM_DESC(debug_state, "Enable/Disable watchdog work to check device state (default="
+		 __MODULE_STRING(MXT_DEBUG_STATE) ")");